Module 3 is all about the ocean. This is a very big subject so we will just be able to touch on a few subjects. During the first week of Module 3 we will focus on the data that the JRH and its crew have been collecting. The second week will focus more on the biology of the ocean and exploring the species that they have encountered.

pH. What is pH and why is it important?

pH is the measure of hydrogen ion concentration, or how acidic or basic something is. The pH scale ranges from 0-14. A pH of 7 is neutral, less than 7 is acidic and greater than 7 is basic or alkaline. pH is measured on a base 10 logarithmic scale, this means that something with a pH of 1 is 10x more acidic than something with a pH of 2. When many people hear acid they think something that will burn or dissolve things. This is not incorrect but things have to be very acidic in order to burn you. The other side of the scale, basic, sounds very innocuous but things that are highly basic can burn and dissolve things as well. Take a look at the image below:

Are you surprised by the pH of any of the above? Because pH is a logarithmic function, slight changes in pH can have a very large impact. For example the human body has an internal pH in the range of 7.35-7.45. If your pH strays too far from this range a number of serious effects on the body can occur.

All living things have ideal pH ranges, some are very adaptable and can live in a wide range of pH levels, others have very specific ranges.

The ocean currently has a pH of around 8.1, this is believed to be a decrease of around 30% from the level it was in the 1700’s. This is a topic that is being studied quite extensively now, as the effects of this decrease are thought to be many and far reaching. The JRH has been measuring pH during their trip in order to contribute to the data on this subject. Here is a data plot of pH that is coming from the boat.

Some scientific models state that the ocean pH will be down to 7.9 by the year 2050. What do you think the effects on the ocean will be if this comes to pass?